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As a response to the desaster at the Fukushima nuclear power plant I've heard the claim that fossil-fuel power plants using coal release more radiation than a nuclear power plant. I searched for some information and found an article supporting this statement in the Scientific American called Coal Ash Is More Radioactive than Nuclear Waste.

This is a topic with huge political and economic interests which makes accurate and reliable information hard to find. I'm now wondering if that comparison of coal ash and nuclear waste is accurate, and also if it is misleading, how it compares to the real-world radiation release.

How much radiation is released by coal and nuclear power plants in regular operation? How do the numbers compare if you include different types of nuclear accidents?

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I would like to know the amount of radioactive waste produced by coal and nuclear plants for a given amount of energy generation (tons per GWh, for instance). Based on some numbers I've read, they seem similar: “a typical nuclear reactor will generate 20 to 30 tons of high-level nuclear waste annually." "For the year 1982, assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively, each typical plant released 5.2 tons of uranium (containing 74 pounds of uranium-235) and 12.8 tons of thorium that year." But how much is a "typical" plant? –  endolith Jul 4 '11 at 17:58
    
interesting question, endolith. And of course there's the little problem that a "typical" nuclear plant most likely has a far higher electrical output than does a "typical" coal fired plant. You have to therefore take the numbers per KWh produced to get any real comparison. –  jwenting Jul 6 '11 at 5:30
    
@jwenting: I already answered my own question below. :) –  endolith Jul 6 '11 at 21:28
    
While not directly related to which releases more radiation, another interesting statistic is deaths / kilowatt-hour. Looking at this statistic,per unit of energy generated, coal causes over 1000 times as many deaths as nuclear or wind and over 100x hydro. forbes.com/sites/jamesconca/2012/06/10/… –  David Oct 15 '12 at 18:52
    
Purely anecdotal, but when I worked at the health-physics department of a nuclear power plant for Atomic Energy Canada in the 1990's, it was commonly accepted among and regularly repeated by my peers that coal power plants released magnitudes more radioactive material than nuclear power plants. It was a point of aggravation for my peers at the time, as the coal plants were relatively unregulated yet the nuclear power plants had significant regulatory requirements. –  Brian M. Hunt Mar 19 '13 at 17:19

3 Answers 3

up vote 52 down vote accepted

The answer to your first question is already in the article you linked. It contains the following referenced quote:

In fact, the fly ash emitted by a power plant—a by-product from burning coal for electricity—carries into the surrounding environment 100 times more radiation than a nuclear power plant producing the same amount of energy.

The paper referenced in the article is here: http://www.sciencemag.org/content/202/4372/1045.short

Radiation doses from airborne effluents of model coal-fired and nuclear power plants (1000 megawatts electric) are compared. Assuming a 1 percent ash release to the atmosphere (Environmental Protection Agency regulation) and 1 part per million of uranium and 2 parts per million of thorium in the coal (approximately the U.S. average), population doses from the coal plant are typically higher than those from pressurized-water or boiling-water reactors that meet government regulations. Higher radionuclide contents and ash releases are common and would result in increased doses from the coal plant.

The paper itself states that this result is only valid not considering nuclear accidents and nuclear waste, nor it considers non-radiological effects:

The study does not assess the impact of non-radiological pollutants or the total radiological impacts of a coal versus a nuclear economy.

Regarding your second question, it can be answered easily:

  • The paper itself speaks about Uranium and Thorium being released by normal operation in less than 10 parts per million - very very low doses
  • A bad nuclear accident leaves kilograms or tons of radioactive elements exposed or emitted
  • Typically nuclear waste is composed of tons of material

So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant.

For example:

  • Living within 50 miles of a nuclear reactor 1 day: 0.09 µS;
  • Living within 50 miles of a coal plant 1 day: 0.3 µS;
  • Living in within 30 km of Chernobyl before evacuation: 3-150 mS (1,000×–50,000× a day of coal plant vicinity)

The first two are data from the image below, the third comes from from Wikipedia


Thanks to Borror0 for the great find. To put things in perspective see the following infograph. At the top left, in blue, you can see the radiations absorbed by living next to a (nuclear|coal) plant. In yellow, the radiation doses of Chernobyl - many orders of magnitude higher.

Radiation

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The radionucleids in coal don't disappear and more than those used in nuclear power. Compare and contrast various nuclear power accidents with events like the Kingston Fossil Plant coal fly ash slurry spill. –  dmckee Mar 19 '11 at 21:44
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@dmckee: radioactivity doesn't go away, but we are talking about very different quantities, with very different dispersion mechanisms. –  Ebenezer Sklivvze Mar 19 '11 at 22:32
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+1 for appropriately incorporating an xkcd reference (even though Randall made it dead easy) :-) –  Patches Mar 20 '11 at 2:28
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"So it is clear that a single nuclear accident widely offsets any "gains" obtained by using a nuclear plant instead of a coal plant." That's a value statement. Taking into consideration everything else (chemical pollutants, the far higher accident rate in non-nuclear plants, etc.) and the equation changes dramatically, and highly in favour of nuclear. –  jwenting Jul 6 '11 at 5:27
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@jwenting I think your statement is more of a value statement than what Sklivvz said. During normal operation, a nuclear plant releases less radiation/radioactive material than a coal plant (actually, you should take waste into account... which "we" still don't know what to do with it), but one severe accident releases more than what you have saved before. Now, saying this is tolerable or not would be a value statement. –  Simon Lehmann Mar 19 '13 at 14:36

Yes, people are exposed to more radiation from coal power plants than from nuclear power plants:

Dosage comparison from Wikipedia:

According to U.S. NCRP reports [source says 92 and 95], population exposure from 1000-MWe power plants amounts to

  • 490 person-rem/year for coal power plants and
  • 4.8 person-rem/year for nuclear plants during normal operation, the latter being
  • 136 person-rem/year for the complete nuclear fuel cycle.

So coal power plants are irradiating you 4 to 100 times as much as nuclear plants. (The complete fuel chain dose for coal is not known.)


And to answer my own question, coal power plants and nuclear plants produce similar amounts of radioactive waste:

  • US nuclear

  • France nuclear

  • US coal

    • "The actual average generated power from coal in 2006 was 227.1 GW" (WP)
    • "In 2006, the U.S. consumed 1,026,636,000 short tons (931,349,000 metric tons)" of coal (WP)
    • "Using these data, the releases of radioactive materials per typical plant can be calculated for any year" ... "assuming coal contains uranium and thorium concentrations of 1.3 ppm and 3.2 ppm, respectively" ...
    • they produce 1210 tons of uranium and 2980 tons of thorium ash each year. Combined and divided by energy produced
    • = 2.1 metric tons of radioactive waste per TWh

So, for a given amount of energy, the tiny fraction of uranium and thorium ash created by coal power plants is similar in mass to the total amount of radioactive waste produced by nuclear plants, which is mostly uranium. I don't know how much of this is stored in ash ponds vs dumped into the atmosphere, but it's certainly not held to the same standards as nuclear power plant waste.

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and don't forget that the smoke that comes out of the smokestacks of those coal fired plants (there's some even after filtering) contains ash (which is somewhat radioactive as noted) that isn't part of the amount of waste mentioned here. –  jwenting Jul 7 '11 at 5:30
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@jwenting: This is the ash. I'm just not sure how much is released in smoke and how much is stored in ponds. Another answer says there's a EPA regulation that only 1% can be released as smoke? –  endolith Jul 8 '11 at 3:08
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It's the stored ash only (at least if the figures are based on similar data to what I've seen during graduation work), the stuff removed from the burners and piled onto ash heaps and dumped into holes and covered over. And do the math, even 1% of that much is a lot... –  jwenting Jul 11 '11 at 6:48
    
What is that "fuel cycle" mentioned in the source you cite? The diagrams I have seen about coal/gas/oil/uranium mining and use for electricity generation don't contain any cycles (except for some use of reprocessed uranium). –  Simon Lehmann Mar 19 '13 at 14:46
    
@SimonLehmann: I assume it means that the "490 person-rem/year" is only the pollution from the coal powerplant smokestacks themselves, and not the pollution from mining coal/transporting coal/transporting ash/burying ash/ash running off into fields and contaminating food/etc. (Which would be higher, but probably not enormously higher. I would guess the smokestacks cause the majority of irradiation.) –  endolith Mar 19 '13 at 14:59

Although the concentration of Uranium and Thorium in coal is extremely low, a typical 1000 MW coal fired plant burns about 4 million tons of coal every year. This results in an unregulated release to the environment of 5.2 tons of Uranium along with 12.8 tons of Thorium from a single coal plant each year. This does not include the large amounts of radium, radon, polonium and potassium-40 that is also released from coal plants. Please refer to the Oak Ridge National Laboratory article "Coal Combustion: Nuclear Resource or Danger" by Alex Gabbard for more information on this subject. http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

Nuclear power plants are owned by electric utilities which also run coal fired plants, it is not in there best interest to point out the fact that radiological releases from coal plants exceed those from Nuclear plants.

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